The idea might be great for limiting waste, but it won't make thing less expensive. Most mass manufacturers, like other people say, keeping the steel waste to minimal, since waste steel is waste money for them.
Your example, or most other of the same idea, limits the number possible and practical usage designs for the sake of production efficiency. You have to avoid all the curves, possible ergonomic and more specialized shape (like clip point and drop point). The design will almost always ended up with some more sheepsfoot style. They all have compromise.
Generally speaking, the heat treat is the more expensive and polluting (if you consider it waste) step in knife making since it consumes a lot of energy. Then grinding requires some level precision and material removal, and different steel also more suitable with different grind type, which again affecting the price. And by the way, cutting occurs before those steps, when the steel is still soft.
Cutting creates a lot of dust dust, difficult to clean and recycle, it is and environment hazard, a bigger concern than waste. CNC or waterjet machining are nice, but what you do is ultimately still material removal. You still need to clamping the plate down, removing the contour then manually remove some leftover then grind it out. It takes time, use a lot of energy and creates a lot of metal chips, dust and waste. Laser cutting is great, but it is still about the same of having cutting out the contour, it is not no waste because there is no metal chip or dust, just the chip gets melted in the process. I worked in an industrial CNC workshop for a few years, sometimes I have to wear filtered mask to clean the machines.
There is a high efficiency way that almost every big manufactures already use since the industrial era: Stamping.
It 's fast, minimizing chip and dust. The leftover can be rolled up for easy transport for recycle.
